109 research outputs found
Metal chaperones prevent zinc-mediated cognitive decline
© 2014 Elsevier Inc. Zinc transporter-3 (ZnT3) protein is responsible for loading zinc into presynaptic vesicles and consequently controls the availability of zinc at the glutamatergic synapse. ZnT3 has been shown to decline with age and in Alzheimer's disease (AD) and is crucially involved in learning and memory. In this study, we utilised whole animal behavioural analyses in the ZnT3 KO mouse line, together with electrophysiological analysis of long-term potentiation in brain slices from ZnT3 KO mice, to show that metal chaperones (clioquinol, 30 mg/kg/day for 6 weeks) can prevent the age-dependent cognitive phenotype that characterises these animals. This likely occurs as a result of a homeostatic restoration of synaptic protein expression, as clioquinol significantly restored levels of various pre- and postsynaptic proteins that are critical for normal cognition, including PSD-95; AMPAR and NMDAR2b. We hypothesised that this clioquinol-mediated restoration of synaptic health resulted from a selective increase in synaptic zinc content within the hippocampus. While we demonstrated a small regional increase in hippocampal zinc content using synchrotron x-ray fluorescence microscopy, further sub-region analyses are required to determine whether this effect is seen in other regions of the hippocampal formation that are more closely linked to the synaptic plasticity effects observed in this study. These data support our recent report on the use of a different metal chaperone (PBT2) to prevent normal age-related cognitive decline and demonstrate that metal chaperones are efficacious in preventing the zinc-mediated cognitive decline that characterises ageing and disease
Learning music from each other: synchronization, turn-taking, or imitation?
In an experimental study, we investigated how well novices can learn from each other in situations of technology-aided musical skill acquisition, comparing joint and solo learning, and learning through imitation, synchronization, and turn-taking. Fifty-four participants became familiar, either solo or in pairs, with three short musical melodies and then individually performed each from memory. Each melody was learned in a different way: participants from the solo group were asked via an instructional video to: 1) play in synchrony with the video, 2) take turns with the video, or 3) imitate the video. Participants from the duo group engaged in the same learning trials, but with a partner. Novices in both groups performed more accurately in pitch and time when learning in synchrony and turn-taking than in imitation. No differences were found between solo and joint learning. These results suggest that musical learning benefits from a shared, in-the-moment, musical experience, where responsibilities and cognitive resources are distributed between biological (i.e., peers) and hybrid (i.e., participant(s) and computer) assemblies
Musical novices perform with equal accuracy when learning to drum alone or with a peer
The capacity of expert musicians to coordinate with each other when playing in ensembles or rehearsing has been widely investigated. However, little is known about the ability of novices to achieve satisfactory coordinated behaviour when making music together. We tested whether performance accuracy differs when novices play a newly learned drumming pattern with another musically untrained individual (duo group) or alone (solo group). A comparison between musical outcomes of the two groups revealed no significant differences concerning performative accuracy. An additional, exploratory examination of the degree of mutual influence between members of the duos suggested that they reciprocally affected each other when playing together. These findings indicate that a responsive auditory feedback involving surprises introduced by human errors could be part of pedagogical settings that employ repetition or imitation, thereby facilitating coordination among novices in a less prescribed fashion
Modelling the similarity of pitch collections with expectation tensors
Models of the perceived distance between pairs of pitch collections are a core component of broader models of music cognition. Numerous distance measures have been proposed, including voice-leading [1], psychoacoustic [2â4], and pitch and interval class distances [5]; but, so far, there has been no attempt to bind these different measures into a single mathematical or conceptual framework, nor to incorporate the uncertain or probabilistic nature of pitch perception.
This paper embeds pitch collections in expectation tensors and shows how metrics between such tensors can model their perceived dissimilarity. Expectation tensors indicate the expected number of tones, ordered pairs of tones, ordered triples of tones, etc., that are heard as having any given pitch, dyad of pitches, triad of pitches, etc.. The pitches can be either absolute or relative (in which case the tensors are invariant with respect to transposition). Examples are given to show how the metrics accord with musical intuition
Detection of keyboard vibrations and effects on perceived piano quality
Two experiments were conducted on an upright and a grand piano, both either producing string vibrations or conversely being silent after the initial keypress, while pianists were listening to the feedback from a synthesizer through insulating headphones. In a quality experiment, participants unaware of the silent mode were asked to play freely and then rate the instrument according to a set of attributes and general preference. Participants preferred the vibrating over the silent setup, and preference ratings were associated to auditory attributes of richness and naturalness in the low and middle ranges. Another experiment on the same setup measured the detection of vibrations at the keyboard, while pianists played notes and chords of varying dynamics and duration. Sensitivity to string vibrations was highest in the lowest register and gradually decreased up to note D5. After the percussive transient, the tactile stimuli exhibited spectral peaks of acceleration whose perceptibility was demonstrated by tests conducted in active touch conditions. The two experiments confirm that piano performers perceive vibratory cues of strings mediated by spectral and spatial summations occurring in the Pacinian system in their fingertips, and suggest that such cues play a role in the evaluation of quality of the musical instrument
Perception of isolated chords: Examining frequency of occurrence, instrumental timbre, acoustic descriptors and musical training
This study investigated the perception of isolated chords using a combination of experimental manipulation and exploratory analysis. Twelve types of chord (five triads and seven tetrads) were presented in two instrumental timbres (piano and organ) to listeners who rated the chords for consonance, pleasantness, stability and relaxation. Listener ratings varied by chord, by timbre, and according to musical expertise, and revealed that musicians distinguished consonance from the other variables in a way that other listeners did not. To further explain the data, a principal component analysis and linear regression examined three potential predictors of the listener ratings. First, each chordâs frequency of occurrence was obtained by counting its appearances in selected works of music. Second, listeners rated their familiarity with the instrumental timbre in which the chord was played. Third, chords were described using a set of acoustic features derived using the Timbre Toolbox and MIR Toolbox. Results of the study indicated that listenersâ ratings of both consonance and stability were influenced by the degree of musical training and knowledge of tonal hierarchy. Listenersâ ratings of pleasantness and relaxation, on the other hand, depended more on the instrumental timbre and other acoustic descriptions of the chord
Musical events and perceptual ecologies
This paper, followed by two responses, discusses the application of ecological theory to an understanding of a number of issues in the aesthetics of music. It argues for an understanding of music as based in event perception, with an expanded conception of the sources that are specified by those events. Building on the theory of affordances, it considers the limitations of an information theoretic conception of musical complexity, discusses the importance of perceptual learning (understood as shaping by a structured environment) in understanding the affordances of music for different listeners, and raises the challenging problem of the terms in which musical materials might be appropriately described. The apparent tension between ecological and aesthetic positionsâin which adaptation and accommodation seem to be at odds with a modernist aesthetic perspective which prioritizes the unsettling and defamiliarizing function of artâis confronted, before the paper concludes with some observations about different disciplinary perspectives on aesthetics, and matters of specificity and generality
Pitch Enumeration: Failure to Subitize in Audition
Background: Subitizing involves recognition mechanisms that allow effortless enumeration of up to four visual objects, however despite ample resolution experimental data suggest that only one pitch can be reliably enumerated. This may be due to the grouping of tones according to harmonic relationships by recognition mechanisms prior to fine pitch processing. Poorer frequency resolution of auditory information available to recognition mechanisms may lead to unrelated tones being grouped, resulting in underestimation of pitch number. Methods, Results and Conclusion: We tested whether pitch enumeration is better for chords of full harmonic complex tones, where grouping errors are less likely, than for complexes with fewer and less accurately tuned harmonics. Chords of low familiarity were used to mitigate the possibility that participants would recognize the chord itself and simply recall the number of pitches. We found that accuracy of pitch enumeration was less than the visual system overall, and underestimation of pitch number increased for stimuli containing fewer harmonics. We conclude that harmonically related tones are first grouped at the poorer frequency resolution of the auditory nerve, leading to poor enumeration of more than one pitch
Emotional ratings and skin conductance response to visual, auditory and haptic stimuli
The human emotional reactions to stimuli delivered by different sensory modalities is a topic of interest for many disciplines, from Human-Computer-Interaction to cognitive sciences. Different databases of stimuli eliciting emotional reaction are available, tested on a high number of participants. Interestingly, stimuli within one database are always of the same type. In other words, to date, no data was obtained and compared from distinct types of emotion-eliciting stimuli from the same participant. This makes it difficult to use different databases within the same experiment, limiting the complexity of experiments investigating emotional reactions. Moreover, whereas the stimuli and the participantsâ rating to the stimuli are available, physiological reactions of participants to the emotional stimuli are often recorded but not shared. Here, we test stimuli delivered either through a visual, auditory, or haptic modality in a within participant experimental design. We provide the results of our study in the form of a MATLAB structure including basic demographics on the participants, the participantâs self-assessment of his/her emotional state, and his/her physiological reactions (i.e., skin conductance)
- âŠ